get_markets_breakdown

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is clear. The description adds valuable context beyond annotations: return scope ('daily buy/sell breakdown'), data granularity ('per individual issue'), code format nuances (5-digit vs 4-digit), and date format examples. This enriches the behavioral understanding without contradiction.

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 well-structured with a summary, return details, plan support, and a parameter list. It is front-loaded with the main purpose. Minor redundancy exists between the first two sentences ('sell/buy by investor type' is repeated), but overall it remains concise and scannable.

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?

The description covers the tool's purpose, parameters, and a return overview. It does not explain how parameters interact (e.g., whether code is required, whether date and date_from/date_to are mutually exclusive, or if a valid query must include at least one date). Since an output schema exists, return structure is covered elsewhere, but input constraints remain ambiguous.

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 0%, meaning the JSON schema provides no property descriptions. The description fully compensates by explaining all four parameters with formats, examples, and edge cases ('4-digit codes match ordinary shares only'). This is essential for an agent to invoke the tool correctly.

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 purpose: retrieving market breakdown data (sell/buy by investor type per issue). It uses a specific verb ('Retrieve') and resource, and distinguishes it from generic list tools by mentioning 'per individual issue' and investor types. However, it does not explicitly differentiate from the sibling tool 'get_equities_investor_types', which may cover similar ground.

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 no explicit guidance on when to use this tool versus alternatives. It mentions a supported plan (Premium) but does not state any exclusions, prerequisites, or comparative use cases. The only implied usage is 'if you need market breakdown data', but no alternative is referenced or distinguished.

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