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

Annotations declare readOnlyHint=true and destructiveHint=false, so no contradiction. The description adds value beyond annotations by disclosing the ranking behavior, the 2-25 institution range constraint, the snapping behavior of reportDate implied by 'latest common quarter', and the partial-name resolution semantics. These are behavioral traits not present in the annotations.

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 with no filler. The primary function and ranking logic are front-loaded, and the minInstitutions usage tip is placed at the end as practical guidance. 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 read-only aggregation tool with 100% parameter schema coverage and no output schema, the description covers the purpose, ranking, key constraint (2-25), and parameter intent. It omits explicit mention of return format, but without an output schema that is a minor gap given the tool's straightforward list-oriented nature.

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 coverage is 100%, so the baseline is 3. The description adds meaning beyond the schema by explaining the purpose of minInstitutions in the ranking context ('shared by multiple filers') and by framing institutionNames as supporting partial names and CIKs with ambiguity resolution. This enriches but does not reinvent the schema.

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 clearly states the verb ('Combine'), resource (institutions' 13F portfolios), and ranking logic (holder count, then combined value). It distinguishes itself from single-institution tools by emphasizing multi-institution consensus, though it does not explicitly name sibling alternatives like GetFundsHoldingStock or GetTopHolders.

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 conveys context via 'latest common report date' and 'positions shared by multiple filers', and gives a concrete tip (set minInstitutions to 2+ for shared positions). However, it does not explicitly state when to prefer this over similar tools (e.g., GetInstitutionPortfolio, GetFundsHoldingStock) or when NOT to use it.

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