Batch convert images

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

Annotations cover the safety profile (not read-only, not destructive, not idempotent, closed-world), and the description adds behavior beyond them: it continues past bad files and reports each error, writes into outputDir, and caps at 200 files. 'Runs entirely on this machine' mostly restates openWorldHint=false, so it is slight redundancy rather than new information.

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?

Four dense sentences, roughly 60 words, front-loaded with purpose then mechanics. Every clause earns its place except 'Runs entirely on this machine', which duplicates the openWorldHint annotation.

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 an 8-parameter mutation-ish utility with no output schema, the description covers input sources, output destination, error behavior, and the batch limit. It omits what the tool returns (per-file results?) and any permission/'allowed root' constraint implied by the directory-relative parameters.

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 all eight parameters (zip vs separate files, format enum, quality, metadata handling, input/output dirs) are already fully documented in structured fields. The description adds only the aggregate notion that results go to outputDir as separate files or a single archive, which is baseline-level value.

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 (convert) and resource (images) with explicit scope: 'several local images at once, from a list of paths and/or a directory'. The phrase 'several ... at once' implicitly but clearly distinguishes this from the singular sibling convert_image.

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?

Gives concrete input sources (path list and/or non-recursive directory) and a hard operational limit of 200 files per call, which helps an agent decide applicability. It never explicitly says when to prefer convert_image over this tool, so exclusions are left implicit.

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