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

Annotations already declare the profile: non-readOnly, idempotent, non-destructive, closed-world. The description adds a genuine behavioral constraint with 'approved expert', implying the call can fail on a non-approved target, but it never says what happens then or whether the operation is reversible. With annotations carrying the safety profile, this is adequate but thin.

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?

A single short sentence with no filler, front-loaded with the verb. It is appropriately sized for a one-parameter mutation, though the brevity borders on under-specification rather than tightness.

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 with no output schema and zero parameter description coverage, the description should at minimum point the agent to where expertId comes from and relate the tool to unfavorite_expert/list_favorites. Neither is present, so an agent must go outside the definition to call it confidently.

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 0% for the single parameter, so the description is the only place meaning could be added — and it says nothing about expertId. It does not indicate that the ID should come from search_experts or get_expert, nor any format or length expectations, leaving the agent to infer the source of the identifier.

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 states a verb ('Saves') and resource ('an approved expert on your account'), but it is close to a restatement of the name/title 'Favorite an expert'. The only real increments are 'approved' (a prerequisite) and 'on your account' (per-account scoping); it does not distinguish itself from list_favorites or unfavorite_expert, which sit right next to it in the toolset.

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?

There is no guidance on when to call this versus unfavorite_expert or list_favorites, and no mention of what to do if the expert is already favorited or is not approved. The implied prerequisite ('approved') is stated but not actionable — nothing tells the agent how to verify approval before calling.

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