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

Beyond the annotations (readOnly=false, destructive=false, idempotent=false), the description discloses two behaviors an agent cannot infer from structured fields: the call consumes plan quota, and is_virtual is silently coerced to false when Google Calendar/Meet conditions are not met. The coercion is the standout detail. It stops short of saying what is returned or whether creation fails on hitting the plan cap.

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, front-loaded sentences with no filler; the core action leads and the caveats follow. The telegraphic phrasing ('Meet links are on') is slightly compressed but still parseable.

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 non-idempotent mutation with 10 parameters, low schema coverage and no output schema, the description covers the trickiest parameter and the quota side effect but leaves the price/duration/display_order semantics undefined. An agent would need to guess how price interacts with price_unit before calling.

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 20% across 10 parameters, so the description is expected to compensate and largely does not. The is_virtual explanation repeats the schema's own description almost verbatim, while price_unit's enum semantics (fixed vs hourly vs per_unit vs quote), duration_minutes, display_order, category_id and active receive no explanation at all. Only the image-exclusion note adds genuine beyond-schema meaning.

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 ('Create a service'), which an agent can immediately place alongside list_services, get_service, update_service and delete_service. It does not explicitly name those siblings to differentiate, but the create/read/update/delete naming makes the split unambiguous.

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?

'Counts against the plan cap' flags a real precondition (quota consumption) an agent should weigh before calling, and the create-vs-update distinction is implied by the name. However, there is no explicit when-to-use/when-not guidance and no pointer to update_service for modifying an existing record.

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