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

Annotations already establish the safety profile (readOnlyHint=false, destructiveHint=false, non-idempotent). The description adds real behavioral context beyond that: the report is stored but NOT applied to either calendar, and the result is returned as "accepted true and applied false." It also constrains content (no names/emails). This is useful side-effect disclosure, though the "accepted true / applied false" wording is cryptic without the output schema.

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?

Purpose is front-loaded in the first sentence, which is good. But two sentences verbatim restate schema constraints for claim and source_url, spending words without adding information. The trailing "This is not a calculation" is placed last rather than with the other scoping notes, slightly weakening structure.

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?

The tool is low complexity (4 fully-documented params, output schema present), so the description need not explain return values. It covers the essential facts: this is a write that stores a report without applying it, with content restrictions. The one gap is that the "accepted true / applied false" semantics lean on the output schema rather than being self-contained.

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 schema already documents all four parameters, including the date format, calendar enum, claim length, and URL constraints. The description largely repeats schema content ("claim is one line of at most 500 characters," "source_url is an http or https URL with no username or password"), adding only the marginal "Do not send a name or an email" restriction. Baseline 3 is appropriate.

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 opening sentence states a specific verb and resource: "Store a suspected wrong closing for later review." This clearly distinguishes it from the calendar-computation siblings (add_business_days, roll_date, etc.), which never store anything. An agent can identify what this tool does and why it differs from its 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?

Usage is implied by "suspected wrong closing for later review," and the description gives explicit exclusions: "This is not a calculation" and "The report is not applied to either calendar." This routes the agent away from mistaking it for one of the sibling calculation tools. However, no alternative tool is named, so it stops short of a full when/when-not/alternatives statement.

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