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

The description goes well beyond the annotations, disclosing that this tool mutates the food diary and calendar, rebuilds life_state, tags companions on the mirrored event, and requires API key/OAuth while share tokens cannot write. It also reveals failure semantics: unknown companion names do not fail the food write. No contradiction with the annotations 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?

The description is dense but every sentence contributes: purpose, trigger, example, optional fields, alias behavior, side effects, and auth requirements. The 'MUTATES' emphasis and example are front-loaded, though the sentence about resolution and rebuilding life_state is slightly compressed and might be clearer with minor restructuring.

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 13-parameter mutation tool, the description covers the essential behavioral context, auth constraints, side effects, and a concrete usage example. The output schema exists, so return-value documentation is not the description's burden. The description is sufficiently complete for an agent to select and invoke the tool correctly.

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 coverage is high at 85%, so the schema already documents most parameters. The description adds meaningful semantics not in the schema: alias resolution for Mum/Dad, expansion of 'family' to CRM rows, precedence of consumed_at over meal_period, and that unknown names do not fail. These details help an agent populate fields correctly.

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 specific verb and resource: 'MUTATES the authenticated user Food Diary and calendar.' It clearly distinguishes the tool's scope from siblings by framing it around eating/drinking events and explicitly says not to store such data as chat memory. The example further anchors the purpose.

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 description explicitly says 'Use when they ate or drank' and warns 'do not store this as a chat memory,' giving clear contextual direction. It does not explicitly name a sibling tool as an alternative, but the eating/drinking trigger is specific enough to route an agent correctly.

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