instagram_search_signals

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful beyond-annotation context: 'Contacts nothing and calls no model' and 'measures what is already on disk' (no network or external dependency), plus a concrete breakdown of how each signal is derived. This enriches the behavioral picture beyond what the annotations state.

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 well-structured with clear sections (purpose, behavior/signals, args, returns) and front-loads the core purpose in the opening line. It is somewhat verbose — the granular per-signal derivation detail and the Returns enumeration could be trimmed since an output schema exists — but the information density is high and nothing is filler.

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 tool of this complexity (measuring six distinct signals), the description covers what each signal is derived from, notes the appearance limitation, and confirms no model/network calls. An output schema exists, so the Returns section is redundant but not harmful. The single parameter is fully documented in the schema, and the sibling context is clear. Coverage is thorough given annotations already carry the safety profile.

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% — the sole parameter `search_id` is already documented in the schema as 'The search to analyse.' The description's Args section merely restates this exact wording, adding no syntax, format, or validation detail on top. This is the baseline 3 where 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?

The description states a specific verb ('Read') and resource ('every enriched candidate against the persona') and makes the scope unmistakable: it is a free, disk-only signal measurement tool. It clearly differentiates from sibling tools like instagram_search_enrich or instagram_get_style_profile by framing itself as the free pre-vision analysis step, so an agent can select it without opening the schema.

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 explicit when-to-use guidance: 'run it before spending anything on images, and let vision see only what survives it.' This routes the tool ahead of vision-based analysis while noting its limitation ('no free signal can reach' appearance). It lacks an explicit 'do not use when...' clause or named alternative sibling, which keeps it from a 5, but the actionable ordering advice is strong.

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