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

The description goes well beyond the readOnlyHint annotation by disclosing side effects and expected behaviors: results are auto-stored, new/seen splitting, watcher-mode reporting rules, how to link returned object IDs, and the found_by_object_id requirement. No contradiction with the annotation is apparent since the readOnlyHint refers to external state, not the internal memory side effect.

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?

The description is dense but not bloated; every sentence adds operational detail an agent needs. It front-loads the core purpose before moving into side effects and usage nuances. It could be split into clearer sections, but the content justifies the length.

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?

Despite having no output schema, the description covers the essential return semantics (new/seen), the object-ID linking convention, storage behavior, auth fallback, scheduled-watcher handling, and the special parameter. This is a complete operational picture for calling the tool correctly.

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 description adds value by explaining when found_by_object_id should be passed versus omitted and why it matters, and by reinforcing that query uses X search syntax. This is a modest but real improvement over the schema alone.

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 states a specific verb and resource: 'Search recent public posts on X (Twitter) by keywords.' It also scopes the search to roughly the last week, which clearly distinguishes it from sibling tools like get_my_tweets or web_search.

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?

It gives clear context for when to use this tool: searching recent public X posts by keywords and the account-connection requirement. It doesn't explicitly name sibling alternatives to exclude (e.g., get_my_tweets for one's own posts), so it stops short of full when/when-not guidance.

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