twitter_article_update_cover_media

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

Annotations are minimal (readOnlyHint: false, destructiveHint: false), so the description rightly carries the burden and adds context: acts 'AS your authenticated account,' requires write capability, clarifies it does NOT upload, and discloses the return shape ('updated article object with cover_media populated'). No contradiction with 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?

Four information-dense sentences, front-loaded with the core action in the first clause. Use of ALL-CAPS emphasis ('ALREADY-UPLOADED,' 'NOT') aids scanning. No wasted words; every sentence 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?

For a 7-param, 2-required tool with no output schema and no enums/nesting, the description covers the key gaps: return shape, auth requirements, and cross-tool dependencies. Adequately complete given the moderate complexity.

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 baseline is 3. The description adds genuine value by cross-referencing which sibling tool produces each identifier (media_id from twitter_media_upload, id from twitter_article_create/list), going beyond what the schema alone provides.

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?

Specific verb+resource: "Attach an ALREADY-UPLOADED image as the cover of a DRAFT or PUBLISHED article." Clearly distinguishes from siblings by explicitly contrasting with twitter_media_upload and naming provenance tools (twitter_article_create/twitter_article_list).

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?

Explicit workflow guidance: 'call twitter_media_upload first and pass the media_id it returns' gives when-to-use and sequencing, 'This does NOT upload' gives exclusions, and 'Requires an authenticated session with write capability' states preconditions. Names exact sibling tools for ID provenance.

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