generate_diagram_url

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

With no annotations provided, the description carries the full burden. It discloses that the tool generates URLs (not files) and mentions the external service Kroki.io, which adds useful context. However, it doesn't cover behavioral aspects like rate limits, authentication needs, error handling, or whether the URL is persistent/temporary. The description doesn't contradict annotations (none exist).

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 description is appropriately sized (three sentences) and front-loaded: the first sentence states the core purpose, the second explains inputs/outputs, and the third describes usage. Every sentence earns its place with no redundant information.

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?

Given the tool's moderate complexity (3 parameters, no output schema, no annotations), the description is reasonably complete. It covers the purpose, inputs, outputs, and usage context. However, without annotations or output schema, it could benefit from more behavioral details (e.g., URL characteristics, error cases). The 100% schema coverage helps compensate.

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 three parameters thoroughly. The description adds minimal value beyond the schema: it mentions 'Mermaid diagram code or other supported diagram formats' which aligns with the 'type' and 'content' parameters, but doesn't provide additional syntax or format details. Baseline 3 is appropriate when the schema does the heavy lifting.

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 description clearly states the tool's purpose: 'Generate a URL for a diagram using Kroki.io' with specific verbs ('generate', 'takes', 'returns') and resources ('Mermaid diagram code or other supported diagram formats', 'URL to the rendered diagram'). It distinguishes from the sibling tool 'download_diagram' by focusing on URL generation rather than downloading.

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 description provides clear context for when to use this tool: for generating URLs to display diagrams in web browsers or embed in documents. It implies an alternative (the sibling 'download_diagram' likely downloads the diagram file), but doesn't explicitly state when to choose one over the other or list exclusions.

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