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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real context beyond that: the one-row-per-channel duplication rule and the fact that results are truncated past limit — both non-obvious behaviors an agent would otherwise misread.

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?

Front-loaded with the resource, then the enumeration and the dedup caveat, ending with truncation. Slightly run-on and the fragment 'Returns truncated when there are more than limit' is awkward, but every clause carries 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?

An output schema exists, so return values need no explanation, and the description covers the two things that would trip an agent: per-channel duplication and truncation at limit. Minor gap: it does not say how to retrieve the remainder once truncated (there is no offset parameter).

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. The description earns above baseline by explaining why a company can appear multiple times (once per channel), which gives the channel filter and the row semantics meaning the schema text alone does not convey.

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 ('the competitors the brand tracks') plus the shape of each row (channel-tagged). It is distinguishable from list_competitor_ads and get_competitor_analyses by being the roster itself, though it never names a sibling to contrast with.

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?

Usage is implied by the resource description rather than stated: an agent can infer this is the entry point for the tracked-competitor roster before drilling into ads or analyses. There is no explicit when-to-use/when-not or pointer to alternatives like list_competitor_ads.

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