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

Annotations already mark readOnlyHint=true and destructiveHint=false. The description adds useful behavioral details: the API key is taken from the MCP Authorization or X-Api-Key header, and it refuses unsafe methods and excluded endpoint categories. This goes beyond the annotations and helps the agent understand constraints.

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?

Two concise sentences: the first states purpose and authentication, the second states exclusions. No filler, front-loaded with the core function.

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 generic endpoint caller, the description covers purpose, auth mechanism, and forbidden methods/endpoints. With full schema parameter documentation and safe-operation annotations, this is complete enough. It doesn't specify return format, but that is likely self-evident and not required given no output schema.

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?

Input schema covers all 4 parameters with clear descriptions (e.g., path examples, timeout range, parameters object, maxResponseBytes truncation). The description itself adds little parameter-specific meaning beyond what the schema already provides, so baseline 3 is appropriate.

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 it 'Executes a documented steamwebapi GET endpoint' with the caller's API key. It distinguishes itself from sibling tools (e.g., get_concept, list_games) by being a generic read-only GET caller, and the name/title reinforce this role.

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: use for GET endpoints, pass API key via headers, and it explicitly refuses POST/PUT/PATCH/DELETE plus Proxy, Steam Guard and Tradeoffer endpoints. It doesn't explicitly compare to alternatives (e.g., 'use this for endpoints without a dedicated tool'), but the restrictions and generic nature imply when it should be chosen.

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