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

Annotations declare readOnlyHint and openWorldHint, so safety is covered. The description adds useful behavioral context beyond that: the content is public, and the response contains both metadata and full body paragraphs, telling the agent what it actually gets back rather than just that it is a read.

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 tight sentences with no filler: the fetch semantics and return payload come first, followed by the sibling routing. 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 values need not be detailed, and the description covers purpose, input, and alternatives. It is complete enough to call correctly, though it could note behavior on invalid or non-canonical URLs.

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% with a single url parameter already documented as 'Canonical Collider article URL'. The description repeats 'canonical url' without adding format, example, or resolution rules, so the 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 a specific resource ('public Collider article metadata and body paragraphs'), plus the required input shape ('canonical url'). It also names the sibling discovery tools, so an agent can distinguish it from collider_headlines/collider_news without inspecting either 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 to collider_headlines and collider_news for story discovery and collider_author for writer profiles, which implies this tool is for retrieving a known article. It stops short of stating outright 'use this only when you already have an article URL', so it is clear but slightly implicit.

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