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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered elsewhere. The description adds cost/behavioral context the annotations do not: it is free, costs 'one request to PulseWatch, no payment'. It stops short of describing pagination limits or result volume.

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 short sentences, front-loaded with the cost signal and the core action. The free/no-payment message is stated twice ('Free' and 'no payment'), a small redundancy, though the closing clause also conveys the one-request cost.

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 compensates by naming the returned fields (slug, name, category) and paging behavior. For a trivial two-param read-only lookup this is nearly sufficient; total-count or page-size expectations are the only unaddressed item.

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 both 'page' and 'search' are already documented with defaults and examples. The description only restates 'paged' and the search intent, adding no syntax or format detail beyond the schema. 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?

States a specific verb+resource (list/search vendors) plus the returned fields (slug, name, category) and paging behavior. The routing cue 'before paying' separates it from the paid siblings (pricing, validate_vendor) without the agent needing to open another 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?

Explicit when-to-use: 'Use it before paying to confirm a vendor is tracked and to get its exact slug.' That gives a clear trigger and payoff, but it names no alternative tool or when-not condition (e.g. how it differs from validate_vendor or vendor_status).

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