Get Page Metadata

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

Annotations already declare readOnlyHint, destructiveHint=false, idempotentHint, and openWorldHint, which cover safety and idempotency. The description adds valuable behavioral context (cost comparison and specific metadata returned) without contradicting annotations.

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 extremely concise: two short paragraphs followed by an example. Every sentence serves a purpose, and the structure is clear and easy to read.

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 has only one parameter, rich annotations, and a straightforward output (described as {title, description, canonical, og}), the description is sufficiently complete. It could optionally mention potential errors or edge cases, but the current level is adequate.

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 100% and already describes the 'url' parameter. The description restates it with type and a brief clarification ('The page URL') and provides an example input, adding marginal value beyond the schema.

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 uses a specific verb ('Fetch') and resource ('page metadata'), and clearly distinguishes it from fetching full content by highlighting cost efficiency. It also lists the exact metadata fields returned, leaving no ambiguity about the tool's purpose.

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 explicitly states 'Cheaper than fetching full content when you only need to identify a page,' providing clear guidance on when to use this tool versus alternatives like fetch_url. It does not explicitly name the alternative but strongly implies the context.

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