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

No annotations are provided, so the description carries the full burden. It does disclose one genuinely useful behavioral trait — the returned content is untrusted user-generated input — which is security-relevant context an agent should have. However, it omits permission requirements, rate-limit behavior, and error semantics for an invalid or missing highlight_id.

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, zero filler, with the retrieval purpose front-loaded ahead of the safety caveat. 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 simple single-ID read tool with full parameter coverage and no output schema, the description plus schema provide enough to invoke it correctly, and the untrusted-input note covers the main risk. It would be more complete with a note that highlights must be fetched per user via get_user_highlights first, but nothing critical to the call itself 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?

There is a single parameter and schema description coverage is 100%, so the schema already documents highlight_id as the integer primary key. The description adds nothing beyond the schema about the ID's format or origin. Baseline 3 applies when the schema does the heavy lifting.

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+resource (get highlight by ID) that an agent can distinguish from the sibling list tool get_user_highlights. It also characterizes the resource as user-generated Instagram content, adding domain clarity. It stops short of naming which sibling to use when, but the retrieval purpose is unmistakable.

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?

There is no when-to-use versus when-not guidance and no mention of the natural alternative get_user_highlights for enumerating a user's highlights. The agent must infer that this is the single-item lookup counterpart to the list tool. No prerequisites or context are given.

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