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

Annotations already declare readOnly, idempotent, non-destructive, non-open-world, so the safety profile is covered. The description adds a genuinely useful behavioral detail not in the structured data: content is truncated to 8,000 characters, and lookup is keyed by id or by slug+language. It omits error behavior when slug is given without locale.

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: the first front-loads the usage trigger, the second the return shape and lookup mechanics. No filler and no repetition.

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?

With an output schema present the description need not explain return values, yet it summarizes them usefully and covers both lookup paths. Only the failure mode of a slug lookup without locale is unaddressed, which is minor.

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%, so the baseline is 3. The clause 'looked up by id or by slug plus language' restates what the idOrSlug and locale schema descriptions already state, adding no new format or constraint information.

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 (read/check/quote) and resource (one blog post), then enumerates the returned fields. It explicitly distinguishes itself from show_article_preview ('Not for a visual preview card'), so an agent can route correctly without opening the 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?

Gives a clear trigger ('when someone wants to read, check or quote one blog post') and names the lookup modes plus one explicit exclusion. It does not mention discovery-oriented siblings like search_articles or list_article_translations as alternatives when the target post is unknown.

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