session.mode

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description states this is a read operation ('Get ...'), but there are no annotations (e.g., readOnlyHint or destructiveHint) provided. Thus the description carries the burden. It doesn't disclose whether the tool has side effects (likely not), what happens if the session_id is invalid, or the format of the returned mode. For a query with no annotations, this is minimal disclosure. It doesn't contradict any annotations, so no contradiction.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single short sentence: 'Get session safety/determinism mode.' Every word is necessary, and there is no wasted text. It is clean and front-loaded. This is an example of ideal conciseness for a simple tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the low complexity (1 required parameter, no output schema, no nested objects), the description is fairly complete. It tells the agent what the tool does in a straightforward manner. The only missing context is what the return value looks like (e.g., a string like 'safety' or 'determinism'), but since there is no output schema, this is a minor gap. For a simple query, this is nearly complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, meaning the description must add meaning to the single parameter 'session_id'. The description says 'Get session safety/determinism mode' which implies the session_id identifies which session's mode to retrieve, but it doesn't explicitly describe the parameter's purpose, format, or constraints (e.g., must be a valid open session). With only 1 parameter required, the baseline is 4 for zero parameters, but the schema already defines the parameter name and type, so the description adds minimal additional value. This is acceptable since the parameter name 'session_id' is self-explanatory.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Get session safety/determinism mode.' clearly states the verb ('Get') and the resource ('session safety/determinism mode'), which is specific enough. Among sibling tools like 'session.set_mode', 'session.open', and 'session.list', it is clearly differentiated as a query for the current mode, not for listing, opening, or modifying sessions. However, it doesn't explain that this is likely a read-only operation or how the 'mode' relates to session behavior, which would slightly improve clarity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage: call this when you need to know the current safety/determinism state of a session. However, it provides no explicit guidance on when to use this tool vs. alternatives like 'session.set_mode' or 'session.list'. There is no mention of prerequisites (e.g., session must be open) or exclusions (e.g., not applicable for certain session types). For a simple query tool with a single parameter, this is adequate but leaves an agent to infer context.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.