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

Annotations already declare readOnly, idempotent, non-destructive and openWorldHint=false, so the safety profile is covered. The description adds useful domain semantics (the catalog is third-party and free, suitable for plugin polling) but says nothing about result volume, pagination, or rate limits beyond what the schema states.

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 tight sentences, front-loaded with the resource and immediately followed by the disambiguating negation. The final clause ('Returns endpoints matching your query, filterable by category') largely repeats the schema but does not bloat the text.

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, but the description states what comes back (matching endpoints) and the schema covers all three parameters. Combined with annotations that carry the safety profile, an agent has enough to call this correctly; only return-shape detail is thin.

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 query, category and limit are fully documented in the schema. The description only restates query matching and category filtering, adding no format or syntax detail beyond the baseline expectation.

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 (Search) and resource (catalog of free third-party APIs) plus the consumer context (a private plugin polling for data). The explicit exclusion 'Not TRMNL's own API' distinguishes it cleanly from the Account* sibling tools, which all manage TRMNL account resources.

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?

Gives clear context for when to reach for it: finding third-party endpoints a plugin can poll, with a negative exclusion for TRMNL's own API. It stops short of naming a specific alternative tool or stating preconditions, but the boundary against siblings is unambiguous.

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