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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so safety is covered; the description adds genuine behaviour by disclosing that the return payload is full text and that the id encodes three distinct content shapes. It stops short of saying anything about payload size or truncation for long articles, which would be the one remaining disclosure of practical value.

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?

Three compact sentences, front-loaded with the usage condition before the mechanics, with no redundant restatement of the title or annotations. The dense final sentence carrying the id formats is information-bearing rather than filler.

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 covers return shape and annotations cover the safety profile, so the description only needs usage, scope and id construction — all present. The one residual ambiguity (fetch vs get_article_look) is minor relative to the overall coverage of a two-parameter read tool.

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 baseline is 3, but the description goes beyond the schema's bare "An id returned by search" by showing the literal id syntaxes ("<locale>/<slug>#<anchor>", "look:<id>", "season:<season>"). That materially helps an agent construct or validate the required id rather than just copying it.

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 and resource ("Returns the full text of one item from search") and then enumerates exactly which id forms are in scope: guide section, article look, and colour-season palette page. The agent can tell this apart from get_guide and knows the tool is an id-driven full-text retriever rather than a search tool.

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 an explicit positive context ("For research modes (deep research, company knowledge)") and an explicit exclusion with a named alternative ("In chat, use get_guide instead"). The gap is that it does not say how fetch differs from the sibling get_article_look even though one accepted id form is "look:<id>", leaving a plausible routing ambiguity.

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