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

With no annotations, the description carries the full burden and discloses critical behaviors: the 100-id hard cap and silent truncation, missing ids omitted without error, non-deterministic row order, and that results are untrusted user-generated content. These are exactly the kinds of operational details an agent needs to avoid pitfalls.

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 front-loaded with purpose and cap, then efficiently layers edge-case behavior. Every sentence earns its place, providing actionable detail without redundancy.

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 two-parameter batch lookup with no output schema, the description is highly complete: it specifies return shape, edge-case handling (missing ids, truncation, ordering), and a trust warning. Only authentication/rate-limit details are absent, which are likely global concerns.

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 thoroughly. The description adds little param-level meaning beyond what the schema provides (e.g., it restates the cap and string reasoning already in the schema). Baseline 3 is appropriate 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 and resource ('Get Instagram user profiles by pk'), clarifies batch scope ('up to 100 ... in a single call'), and references the sibling tool it shares a return shape with. An agent can immediately distinguish this from single-user or search-based siblings.

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 batch retrieval is the use case but does not explicitly name alternatives (e.g., get_user_by_id for single pks) or state when not to use this tool. Usage is inferable from the cap and batch framing, but no direct guidance or exclusions are given.

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