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

Annotations only say readOnlyHint=true; the description adds substantive context beyond that — what a tracked competitor record carries (matched ad libraries, active ads, leading angle, auction overlap where available) and the interpretive limit of library data. It does not mention pagination or result ordering, which for a list tool this size is the remaining 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?

Three sentences, front-loaded with the resource and scope, then the payload shape, then the scoping override. Dense but every clause carries information; the status/evidence detail could be tightened slightly without loss.

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?

There is no output schema, and the description partially compensates by describing what a tracked competitor record contains and by warning about the meaning of library data. Sufficient for an agent to select and call it correctly; a note on result volume or ordering would close the last gap.

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%, so baseline is 3, but the description genuinely adds semantic weight: it explains that 'suggested' entries come with per-suggestion evidence and that 'tracked' entries carry a summary payload, telling the agent what each enum value yields rather than just what it filters on. space_id semantics are left to the schema, which already handles them well.

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?

Names the resource (competitors of one business) and the exact scope of the result set — tracked, suggested with evidence, and dismissed. This distinguishes it from get_competitor (singular fetch), suggest_competitors (generation) and track_competitor (mutation) among the siblings without needing to open any schema.

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 states the Space scoping rule and routes the agent to set_active_space or the space_id override, and adds a real usage caveat: library data reflects what a competitor published, not what worked, so the agent knows not to treat it as performance truth. It stops short of naming when to prefer get_competitor or get_competitor_auction over this list call.

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