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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to disclose content, which it does well: ids, overall and per-assistant naming frequency, the brand × assistant board with the brand included, and untracked-brand suggestions. The only gap is nothing about result size, ordering, or what happens when no competitors are tracked, which keeps it from a 5.

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 verb and resource, then the return contents, then the routing sentence to two siblings - a logical order with no filler. The long parenthetical defining the board is dense but each clause carries distinct information, so it stops short of 5 only on readability.

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?

For a single-parameter read tool with no output schema and full annotation coverage, nothing an agent needs is missing: it knows the scope, the returned fields, the follow-up actions, and the deeper-dive alternative. Return-value content is described precisely where an output schema would otherwise be expected.

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% and the single projectId parameter is already documented in the schema as coming from list_projects. The phrase 'a site's tracked competitors' reinforces the scoping but adds no format or constraint detail beyond the schema, so baseline 3 applies.

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?

Opens with a specific verb+resource ('List a site's tracked competitors') and then enumerates exactly what the payload contains: ids, per-assistant naming counts, a brand × assistant board, and untracked brands surfaced as suggestions. It also distinguishes itself from get_competitor_report, so an agent can tell the two apart without opening either 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 names the use case ('for the overview and to get a competitorId') and names the alternative it is not ('get_competitor_report goes deep on one rival'). It also routes the follow-up action by tying the suggestion output to add_competitor, giving a clear when/when-not/next-step structure.

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