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

Annotations already declare read-only, idempotent, and non-destructive, which are covered. The description adds value by disclosing the credit cost per tweet, which is behavioral information not in annotations. It doesn't mention caching behavior beyond the 'fresh' parameter, but the credit cost is a significant addition.

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 short sentences, front-loaded with the core action and constraints. No wasted words, and the credit cost is a useful extra.

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 batch read tool with annotations covering safety and idempotency, the description covers the essential purpose, constraints, and cost. There is no output schema, but that is not required. Missing details like caching behavior are minor given the 'fresh' parameter.

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 50% (only 'fresh' has a description). The main parameter 'ids' lacks description, but the description's 'numeric id' and the pattern in schema clarify it. The description adds batch limit and credit cost, which enriches the meaning beyond the schema.

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 clearly states 'Up to 100 tweets by numeric id in one call' with a specific verb (get), resource (tweets), and key constraint (batch by id). It distinguishes itself from single-tweet retrieval and search by emphasizing batch by ID, though it doesn't name the sibling explicitly.

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 implies usage for batch retrieval by IDs, and the sibling list clarifies alternatives (e.g., get_tweet for single). However, it does not explicitly state when not to use (e.g., for search by query or user timeline) or name alternatives, but the batch constraint is implicit.

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