show_context

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds value by specifying exactly what is shown (server, database, schema) but does not provide additional behavioral context such as error conditions or authentication requirements. This is similar to the get_calls calibration example, so a 3 is appropriate.

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 concise sentence, front-loaded with the verb and resource. Every word earns its place, and it provides enough detail without any fluff or repetition.

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 zero-parameter read-only tool with an output schema present, the description fully covers what the agent needs to know to invoke it. It specifies the exact information returned (server, database, schema), and the presence of an output schema means return values need not be described in the tool description.

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?

The tool accepts zero parameters, so parameter semantics are trivially satisfied. Per the rubric, a baseline of 4 is given for 0 params, and the description adds no unnecessary param information. It could not add more meaning beyond the empty schema.

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 uses a specific verb ('Show') and clearly identifies the resource ('current PostgreSQL session context') with its components (server, database, schema). This clearly distinguishes it from sibling tools like list_databases or list_tables, which list available resources rather than showing the current session's context.

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 provides clear context for when to use the tool: to display the current session context. It does not explicitly state when not to use it or mention alternatives, but for a simple read-only introspection tool, the intended usage is clear from the description alone.

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