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 goes further by disclosing the CSV return format, pagination behavior, the meaning of a null pct (a known data-quality issue, not a true zero), and the fallback to JSON candidates for ambiguous symbols. It does not cover auth needs or rate limits, but the added behavioral context is substantial.

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 dense, front-loaded with the core purpose, and every sentence contributes distinct information: instrument specificity, CSV/pagination mechanics, null-data caveat, and ambiguous-symbol fallback. There is no redundant restatement of the name or schema fields.

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?

Given no output schema, the description must explain return values; it does so adequately by stating the result is CSV with a pct series and describes pagination and ambiguous-symbol fallback. It does not enumerate all CSV columns, but the core data semantics are clear enough for an agent to interpret the output.

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 the baseline is 3. The description adds meaning beyond the schema by explaining the instrument-suffix behavior (voting vs non-voting shares) and the null pct semantics, which are not fully captured in the schema. It also reinforces the from/to, limit, and offset usage in a cohesive narrative.

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 and resource: 'Get the daily foreign-shareholding percentage series for a CSE symbol,' and clarifies the scope (how much of the free float is held by foreign investors, tracked day by day). It does not explicitly name or contrast with any sibling tool, but the resource is unique enough that an agent can distinguish it from get_top20_shareholders or get_quotes without opening other schemas.

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 gives practical guidance on how to use the tool (when to pass an instrument suffix, how to page with offset, how to scope with from/to), but it never states when to use this tool versus alternatives like get_top20_shareholders or get_quotes. Usage is implied by the purpose rather than explicitly contrasted with siblings.

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