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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered structurally. The description adds only that the response is a full record in the requested language; it says nothing about not-found behavior, permissions, or rate limits, so it adds modest value on top of annotations.

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 front-loaded sentences with no filler, the identification method ('by its slug') stated first. The trailing 'etc.' makes the return-field list slightly vague but it is efficient overall.

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 simple two-parameter read with no output schema, the description gives the identifying key, the language option, and a sample of returned fields, while annotations cover safety. Nothing critical is missing for correct invocation, though not-found/error behavior is unstated.

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 0%, so the description must carry parameter meaning. It explains that 'slug' identifies a single deal and that 'lang' selects the response language, covering both parameters beyond the bare schema. It doesn't state the enum values or the default, which are visible in the schema anyway.

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 ('Fetch the full record for a single deal by its slug'), which clearly separates it from list_deals and search_products. It doesn't explicitly name the sibling it contrasts with, so sibling differentiation is implied rather than stated.

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 implied: fetch one deal when you already have its slug, versus list_deals for browsing. There is no explicit when-to-use/when-not guidance or named alternative, so it stays at the minimum viable level.

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