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

Annotations are absent, so the description must carry the burden of disclosing side effects and safety. The verb 'Retrieve' suggests a read-only operation, but the description does not explicitly state that it is non-mutating or explain what happens to the pending message queue (e.g., whether it is consumed or remains). It also does not address error conditions (e.g., session not found) or authorization requirements. This lack of behavioral disclosure is a gap.

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, well-formed sentence that front-loads the action ('Retrieve') and lists the three components of the result. It contains no redundant or unnecessary words, making it appropriately concise and structured.

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?

For a single-parameter retrieval tool without an output schema, the description is fairly complete: it specifies the required session context (active) and exactly what will be returned. However, it could be more complete by mentioning the return format or potential error states, but given the simplicity of the tool, this level of detail is sufficient.

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 100% (the only parameter, session_id, is fully described as 'Session UUID'). The tool description does not add any additional meaning beyond the schema, so the baseline of 3 is appropriate; the description simply says 'for an active session', which aligns with the parameter semantics without expanding on format or constraints.

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 clearly states the verb 'Retrieve' and the specific resources: current field values, computation transcript, and pending message queue for an active session. This is specific enough to distinguish it from siblings like 'push_session_action' (which modifies) or 'get_calculator_schema' (which retrieves schema, not session state).

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: use this tool when you need to inspect a session's current state. However, it does not explicitly mention alternatives or when not to use it (e.g., comparing with 'calculate' or 'push_session_action'). There is no exclusionary guidance, but the purpose is clear enough to infer appropriate use.

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