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

Beyond the annotations (readOnlyHint=true, destructiveHint=false), the description adds substantial behavioral details: defaults to the latest quarter, grouping via groupBy, markdown table output sorted by % descending, unclassified stocks collapsed into a single row, and ambiguous partial names returning candidates instead of silent selection. This enriches the agent's understanding of what the tool actually does.

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 three sentences long, each earning its place: the first states the main function and grouping options, the second describes the output format and sorting, and the third gives a crucial usage hint about name resolution. It is front-loaded with the core purpose and contains no fluff or 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?

There is no output schema, so the description properly explains the return format (markdown table, sorted by % of portfolio, unclassified row at the end). It also documents defaults for reportDate and groupBy, and warns about ambiguous name behavior. For a tool with 3 parameters and no output schema, this covers all essential aspects an agent needs to use it correctly.

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 a baseline of 3 is appropriate. The description does not add significant new meaning to the parameters beyond the schema: groupBy's meanings and reportDate's snapping behavior are already in the schema, and institutionName's ambiguous partial handling is also in the schema. The only slight addition is the usage guideline to use SearchInstitutions for exact CIKs, which is more of a usage guideline than a semantic enrichment.

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 tool's function: getting an institution's 13F portfolio allocation for a given report quarter, grouped by industry or sector. It uses a specific verb ('Get') and identifies the resource ('institution's 13F portfolio allocation') with clear scope (grouping levels). This distinguishes it from sibling tools like GetInstitutionPortfolio or GetFundHoldings by emphasizing the sector/industry rollup.

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 provides an explicit alternative: 'Use SearchInstitutions for an exact CIK' and warns that ambiguous partial names return candidates. This gives clear guidance for the institutionName parameter. However, it does not explicitly contrast with other allocation tools (e.g., GetInstitutionPortfolio), so it lacks a full when-to-use vs. alternatives discussion, but the context is sufficiently clear.

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