Catalog overview

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

No annotations are provided, so the description carries the disclosure burden. It communicates a read-only, aggregate view through 'High-level snapshot' and specifies the output categories, which conveys non-mutating behavior. However, it does not explicitly state that no changes are made, nor does it mention caching, freshness, or permission requirements.

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 sentences: the first fronts the value proposition and returned content, the second gives a usage cue. No filler or repetition; every clause contributes to helping an agent decide to call it.

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 parameterless overview with no output schema, the description names the key return dimensions (site info, active opportunities, type counts) and explains why that matters (selecting type slugs). It is complete enough to invoke correctly, though 'site info' remains somewhat vague.

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?

The input schema has zero parameters and 100% schema description coverage, so there are no parameter semantics for the description to add. Baseline 4 applies because nothing is left ambiguous for callers.

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?

Description uses a specific verb/resource pair ('High-level snapshot of the Opportunities Circle catalog') and enumerates the exact dimensions it covers (site info, active opportunity count, type breakdown). The phrase 'Good first call' plus the sibling list distinguishes it as the catalog-level overview rather than a search, get, latest, or listing operation.

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 states when to call it ('Good first call to understand what's available and which type slugs to use'), giving a clear entry-point context. It does not explicitly name alternatives or exclusions, but the sibling set and the 'first call' framing make the boundary clear.

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