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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description reinforces and extends this with concrete operational context: 'nothing is saved', 'Limited to 25 suggestions per hour per user', 'each call takes a few seconds and costs no credits', and 'Requires an active subscription or free trial.' This goes well beyond what annotations provide and matches them without contradiction.

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?

Four dense sentences, all earning their place: core purpose, non-save behavior, workflow guidance, and operational constraints (rate limit, latency, cost, auth). The most important scoping information is front-loaded and there is no filler or repetition of schema content.

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?

Given an output schema exists (so return values need no explanation), only two well-documented parameters, and rich annotations, the description covers everything an agent needs: rate limit, cost, latency, auth prerequisite, side-effect-free behavior, parameter guidance, and the follow-up workflow. Nothing essential is missing.

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 schema already documents both parameters well. The description adds minor reinforcement ('Pass website_id when the account has several websites') and explains how inputs are used ('using its brief, target keyword and the website profile'), but it doesn't add materially new meaning beyond the schema. Baseline 3 is appropriate.

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?

The description uses a specific verb and resource ('Asks the AI for an alternative headline for a pending scheduled article') and explicitly distinguishes itself from sibling tools by stating 'It only returns a suggestion: nothing is saved.' This draws a clear line against update_article_headline and update_scheduled_article, so an agent can tell them apart without opening schemas.

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?

The description gives clear context on when it applies — for pending scheduled articles, using brief, target keyword and website profile, avoiding duplicates already in the calendar — and names the follow-up tool ('Apply it with update_scheduled_article once the user picks one'). It lacks explicit exclusions or a comparison to similar siblings like regenerate_headlines, so it stops short of a 5.

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