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

Annotations already declare readOnlyHint=false, idempotentHint=false and destructiveHint=false; the description adds the key behavioral fact those annotations cannot convey: 'Lo que mandas sustituye esa parte y sube la versión' – partial replacement plus a version bump, which explains both the write semantics and why the call is non-idempotent. It stops short of saying what happens to fields not supplied or what the response contains, so it is not 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?

Four short sentences, front-loaded with the core purpose, then ownership, then mutation behavior, then parameter hints – no filler. The phrasing is slightly telegraphic ('Con ref, dónde está ya escrita'), which costs a little readability, but nothing is wasted.

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 5-parameter mutation tool with nested objects and no output schema, the description covers purpose, ownership scope, the replace-and-bump behavior, and the two non-obvious parameters. What is missing is the partial-update edge case (setting visual without voice) and any note on where the previous version goes, which is a modest gap rather than a crippling one.

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 every parameter is already documented, which sets the baseline at 3. The description does add the replacement semantics for voice/visual ('sustituye esa parte') and reinforces the ref/from roles, but it repeats rather than extends the schema on ref and from and says nothing about how the nested voice/visual sub-fields are merged.

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+resource: define the project's brand, split explicitly into 'voice' (how it writes) and 'visual' (how it looks), and clarifies ownership with 'Es de la marca, no del usuario'. An agent can tell what it does without opening the schema. It does not, however, differentiate itself from nearby siblings such as add_brand_example or save_format, so it falls short of a 5.

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 conditional usage for two parameters ('Con ref, dónde está ya escrita; con from, usar la de otro proyecto'), which is genuine routing guidance. But it never says when to call set_brand versus add_brand_example, or what situations to avoid (e.g. when only adding an example rather than redefining the whole brand). Usage is implied by the verb, not spelled out.

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