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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and closed-world scope, so safety is covered. The description adds genuinely useful context beyond that: the result is 11 styles rendered as pictures with names and short descriptions, which tells the agent what the payload looks like and why the call exists. It does not say how the language parameter affects the rendered output, which keeps it below a 5.

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 resource and return contents front-loaded and the user intent appended. Nothing is repeated across the title and description, and no sentence is filler.

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?

This is a simple, non-required-parameter read tool with no output schema, and the description compensates by describing the return payload (11 styles, pictures, names, descriptions). Only the effect of the language parameter on the output is left unstated, a minor gap for a tool of this complexity.

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?

There is a single optional 'language' parameter with 100% schema description coverage including an ISO-code example and default. The description says nothing about the parameter, so the schema carries the full burden and the baseline of 3 applies.

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 ('Shows the 11 Klipa subtitle styles') and even specifies the presentation form ('as pictures, with their names and a short description'). No sibling tool in the catalog offers style previews, so the agent can identify this as the discovery/selection tool without ambiguity.

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 trailing clause 'so the user can see them and pick one' implies the usage context (a preview step before choosing a style, likely ahead of add_subtitles), but it never says when to call it versus just calling add_subtitles directly, and names no alternative. Usage is implied rather than stated.

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