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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower. The description adds two useful facts beyond the annotation: it is backed by POST /opportunities/search and it returns a paginated result set. It says nothing about the shape of returned records, total counts, or rate limits.

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 purpose and free of padding. The clause "returns a page of opportunities" overlaps slightly with "All filters optional" as a general statement, but nothing is wasteful.

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 an 11-parameter search tool with no output schema, the description covers purpose and pagination but does not convey what a returned opportunity contains or how to page through all results. It is minimally sufficient given the readOnly annotation, but leaves the agent to open the schema for anything operational.

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% and each of the 11 parameters carries its own description (including enum meanings for status_ids), so the schema does the heavy lifting. The description adds no filter syntax or format detail beyond the schema; baseline 3 is appropriate.

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 (search/list opportunities, clarified as deals), which is distinguishable from the create/get siblings by name and intent. It stops short of explicitly contrasting with e.g. copper_get_opportunity or copper_search_companies, but the purpose is unambiguous.

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?

"All filters optional" implies a broad listing/query use case and the pagination note implies result-set traversal, but there is no explicit when-to-use guidance or mention of the alternative tools (get_ for single records, create_ for writes). Usage is inferable rather than stated.

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