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

With no annotations, the description carries the full behavioral burden. It discloses the partial-update contract, the 0-100 range for brand voice values, and the allowed category/gender values, but it says nothing about whether omitted fields are preserved, whether supplying brand_voice replaces all four axes or merges, or what permissions are needed. Those are material gaps for a mutation tool with nested objects.

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 dense sentences, action stated first followed by the partial-update rule and the constrained vocabularies. No filler, no repetition of the tool name.

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 19-parameter mutation tool with nested objects, no annotations, and no output schema, the description is far too thin. It covers two enumerations and one numeric range but leaves the bulk of the surface, the merge/replace semantics of brand_voice and competitors, and the absence of required fields unexplained.

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 only 11% (about_website and the nested brand_voice range), so the description is expected to compensate for 17 undocumented parameters. Instead it spends its words restating the category and icp_gender enums that the schema already encodes, and the brand_voice range that the schema already states, while competitors structure, icp_age_range, icp_geography, sitemap_url and the brand_* fields remain unexplained.

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 ('Update this project's Brain') and immediately clarifies the partial-update contract with 'Send only the fields to change.' It contrasts implicitly with get_brain, but never names the sibling or explains what a 'Brain' object actually holds, so an agent unfamiliar with the domain must infer scope.

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?

'Send only the fields to change' is genuine usage guidance for a PATCH-style tool, which is more than most definitions offer. However, there is no statement of when to prefer this over get_brain, no prerequisites, and no indication of whether it is safe to call repeatedly.

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