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

Annotations already declare readOnly, idempotent, non-destructive behavior, so the safety profile is covered. The description adds value by disclosing the return behavior ('return a normalized slug suggestion'), which matters because there is no output schema. It stops at 4 because it doesn't say what an unavailable/invalid result looks like.

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?

A single front-loaded sentence with no filler; the availability check comes before the secondary normalization behavior. Slightly dense with a parenthetical URL template, but nothing is wasted.

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?

For a one-parameter read-only tool with no output schema, the description covers purpose, URL format, and the fact that a normalized suggestion is returned. The remaining gap is failure/taken-slug semantics, which would make it fully self-sufficient.

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 parameter's format (3-40 lowercase letters, numbers, or single hyphens) and the 'site name to normalize' input mode are already documented in the schema. The description restates the same idea rather than adding new semantics, 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 and resource ('check whether a Wordy Page web address slug ... is valid and available') with the URL pattern shown, plus a secondary behavior (returns a normalized slug suggestion). It does not name or distinguish itself from siblings such as create_or_update_page, so it stops short of 5.

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?

Usage is only implied — an agent can infer this is a pre-flight check before create_or_update_page, but the description never says when to use it, when not to, or that it is the alternative to a creation attempt. No explicit routing to siblings is given.

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