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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the trailing 'Read-only' adds nothing beyond structured data. Where the description does earn credit is in disclosing the shape of the result - coverage metric, ranked clusters, competitor-count ranking, and a per-item proposal-ready flag - which matters because no output schema exists.

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?

It is one dense but front-loaded block: the coverage metric leads, the ranked growth points follow, and the use-case tagline closes. Every clause contributes information, though the catalogue-style list of ranking dimensions makes the sentence long enough to skim past the key ranking logic.

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 only one parameter and rich annotations, the main missing element is the return shape, which the description partially covers by enumerating coverage, clusters and proposal readiness. Still absent is any indication of result volume, cost/latency for what is evidently an analytical query, or whether an empty result means 'no gaps' versus 'no data'.

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?

There is a single parameter with 100% schema description coverage, and the schema already explains that project_id comes from seo_list_projects. The description only refers obliquely to 'the linked site' without tying it to the project_id argument or adding format constraints, so the schema does the heavy lifting and the baseline of 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?

The description names the concrete output: niche search-demand coverage plus ranked growth points consisting of clusters with no page or a weak page, scored by volume and competitor overlap. That is far more specific than a restatement of the title, but it phrases the tool in terms of what it returns rather than naming a distinguishing action, and it never contrasts itself with adjacent tools such as seo_list_clusters or seo_estimate.

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?

'The answer to «what page should we build next»' strongly implies the decision context in which to call it, which is useful. However, there are no explicit when-not conditions, no named alternatives, and no note on prerequisites such as whether research must be run first or a proposal must already exist.

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