Call an API endpoint

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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the bar is lower; the description still adds real value by disclosing that params are validated against official docs and that the response is sanitized (no permission flags, HTML duplicates, credentials, private fields). It omits failure modes and rate/latency behavior, and max_chars handling is covered only by the schema.

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?

Three front-loaded sentences: core behavior first, then alternative routing, then the prompt-injection safety note. No filler, and each sentence carries distinct information.

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?

With no output schema, the description does explain the shape of what comes back (sanitized, previewed when large) and where operation IDs come from. Remaining gap is error/failure behavior for a generic open-world endpoint caller.

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%, so the schema already documents service, operation, params and max_chars thoroughly; the description only adds 'checked against the official documentation' without new syntax or format detail. Baseline 3 applies when structured fields do the heavy lifting.

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?

States a specific verb and resource ('Calls one read-only endpoint') plus the exact source of valid operations (api_list_endpoints), which cleanly separates it from the concrete forum_* and market_* siblings it names.

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?

Explicitly routes the agent: 'Prefer the dedicated forum_* and market_* tools when they fit: their output is more compact,' and ties the operation parameter to api_list_endpoints. When-to-use and when-to-prefer-an-alternative are both stated.

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