MCP Action Firewall

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

With no annotations provided, the description carries full burden for behavioral disclosure. It mentions returning an output schema (which aligns with the output schema context signal), but fails to disclose whether the operation is idempotent, what determines the returned content structure, or any side effects. The link between the 'location' parameter and the returned content is unexplained.

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?

Single sentence of 12 words is appropriately brief and front-loaded. However, brevity here results in under-specification rather than efficiency—given the tool has an output schema and enum constraints, a bit more context could have been added without hurting conciseness.

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 only 1 parameter with 100% schema coverage and an output schema present, the description meets minimum requirements. It acknowledges the output schema aspect (relevant to the output_schema context signal), but fails to explain what the structured content represents or why the location parameter affects the response.

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 coverage is 100% (location parameter has description 'Choose city' and enum values). Per the rubric, with high schema coverage the baseline is 3. The description makes no mention of the location parameter or its impact on results, but the schema adequately documents inputs without requiring description supplementation.

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 states it 'Returns structured content' but this is vague—it doesn't specify what kind of content (user profiles? system data?) or how it differs from sibling tools like get-annotated-message or get-resource-reference. The mention of 'output schema for client data validation' is useful but insufficient to distinguish purpose.

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?

No guidance provided on when to use this tool versus alternatives like echo or get-resource-reference. No prerequisites, constraints, or 'when not to use' advice is included. The agent has no signal about whether this is for testing, production data retrieval, or specific validation workflows.

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