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

With no annotations, the description carries the burden; it does disclose a real behavioral constraint (coverage starting 1970) and implies a read-only listing. It says nothing about ordering, grouping by year, pagination, or whether results are capped, which an agent would want to know before a broad query.

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 well-formed sentence with the scope constraint front-loaded and no filler. It is efficiently sized, though the brevity comes at the cost of the parameter and return-behavior gaps scored elsewhere.

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 4-parameter tool with a 31-value enum, no annotations, and no output schema, one sentence is not enough. The genre taxonomy and limit semantics are undocumented anywhere, leaving an agent unable to use the main filtering capability 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 0%, so the description must compensate, and it only clarifies month/day as a calendar date. The 'genre' parameter has 31 opaque enum values (kohaku, takarazuka, recaward, cosme) that are never explained, and 'limit' (max 200) is not mentioned at all.

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?

Specific verb ('List') plus resource ('notable things that happened or were released') with a clear temporal scope ('on a given calendar day... from 1970 onward'). It is distinguishable from siblings like get_month or search_chronodrawer, though it never explicitly contrasts itself with them.

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 the phrase 'given calendar day (month and day)', so an agent can infer this is the anniversary lookup tool. However, there is no explicit when-to-use guidance, no mention of how it relates to get_month or person_timeline, and no stated exclusions.

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