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

Annotations already declare readOnlyHint=false and destructiveHint=false, and the description merely restates that this is a write operation. The 'confirm is not required by the Excel' line is opaque jargon that adds no usable behavioral context (no permission requirements, no effect on unspecified fields, no side-effect description).

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 purpose is correctly front-loaded in the first clause, but the second sentence is confusing and low-value. Two sentences, one of which does not earn its place.

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, the description plus annotations and schema-derived auth param docs cover the safety profile, but it does not explain which fields are editable or how multiple auth parameters interact. Adequate but with visible gaps.

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 63%, which sits in the middle band, and the description adds nothing about the parameters themselves (which fields such as name/date are updatable, what holiday_id must reference). Baseline 3 is appropriate since the schema carries most of the load but the description does not compensate for the uncovered third.

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 ('Updates a holiday') and even names the API route, so the agent can distinguish it from create_holiday, delete_holiday, and list_holidays at a glance. There is no explicit sibling differentiation or scope note, so it stops 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?

No when-to-use, when-not-to-use, or alternative guidance is provided. The trailing 'confirm is not required by the Excel' clause offers no actionable routing or prerequisite information, leaving the agent to infer usage entirely.

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