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

Annotations already declare the operation as read-only, idempotent, non-destructive, and open-world. Beyond that, the description adds useful behavioral detail: content is returned as a string, binary content is base64-encoded, and rejected URIs should be handled by following the named source-specific tool rather than treating the URL as retrieved evidence.

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 front-loaded with purpose, followed by clear USE WHEN, return-value, and post-call guidance. Every section contributes directly to correct tool selection and invocation, with no wasted text.

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?

The tool has a simple one-parameter schema, full schema coverage, an output schema, and annotations covering safety and identity behavior. The description completes the picture by explaining accepted URI types, exclusions, return encoding, and error-handling guidance for rejected URIs.

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%, so the schema already defines the single uri parameter and gives examples. The description adds meaningful semantics by clarifying that the URI must be a registered server resource URI rather than an ordinary web URL and by naming the relevant schemes and fallback tool.

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 states a specific verb and resource: read a registered server resource URI, explicitly not an ordinary web URL. It names the accepted URI schemes and distinguishes this tool from source-specific siblings such as hmrc_get_manual_page, so an agent can identify its role immediately.

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?

It gives explicit USE WHEN guidance tied to judgment://, legislation://, hansard://, and server:// URIs returned by the server. It also states when not to use it for https:// URLs and directs the agent to the source-specific alternative with a concrete example.

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