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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and reach are covered. The description adds that content is 'public' and that body paragraphs are returned, which is useful, but it says nothing about pagination, rate limits, or truncation. Modest added value against annotations that already carry the profile.

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?

Two sentences, zero waste, and the core fetch action is front-loaded ahead of the routing hint. Every clause earns its place.

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?

An output schema exists, so return-value explanation is unnecessary. For a one-param read tool with annotations covering safety, purpose plus sibling routing plus the public-content note is sufficient to invoke correctly.

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% and the single param is fully documented as 'Canonical CBR article URL'. The description restates 'canonical url' but adds no syntax or format guidance beyond the schema, so baseline 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 ('Fetch') and resource ('CBR article metadata and body paragraphs') plus the input source ('canonical url'). It also names the sibling tools it is not, so an agent can distinguish it from cbr_headlines and cbr_author without opening a schema.

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?

Explicitly routes the agent: cbr_headlines for discovering articles, cbr_author for a single writer's profile and recent stories. The when-to-use-this vs. alternatives is fully spelled out.

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