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

Annotations already declare destructive=true, idempotent=true, readOnly=false, so the safety profile is covered. The description adds real context beyond them: it regenerates embeddings as a side effect, it performs a partial update (only provided fields change), and it explicitly does not recreate associated memories. It still does not say what happens when the name is not found or what gets overwritten.

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 short sentences, zero waste, front-loaded with the action and scope before the side-effect and non-effect details. Every sentence carries distinct 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?

For a mutation tool with no output schema, annotations covering the safety hints, and full schema coverage, the description is close to sufficient: it covers lookup key, partial-update semantics, embedding regeneration, and memory scope. Error/not-found behavior and the response shape remain unspecified, a minor gap given the annotations.

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 the baseline is 3. The description only reinforces the schema ('by name', 'body and/or description', optional omission leaves fields unchanged) without adding format or constraint detail beyond what the schema already documents.

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 (Update), resource (an existing Muninn-native skill), and the exact fields in scope (body and/or description), with 'existing' implicitly separating it from muninn_skill_create and muninn_skill_delete. An agent can select this over its skill siblings without opening the 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?

It explains the mechanism ('Finds the skill by name, updates whichever fields are provided') and scopes what it does not do ('Does not recreate the memories'), so usage is implied. But there is no explicit when-to-use vs. muninn_skill_create/muninn_skill_check routing or statement of prerequisites (e.g., skill must already exist).

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