reports_custom

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

No annotations are provided, so description carries full burden. It mentions capabilities like pagination and file output, but does not disclose whether the tool is read-only, required permissions, rate limits, or side effects. Partial transparency is given by listing features, but not comprehensive enough for a complex tool.

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?

Three concise sentences that front-load purpose and capabilities, then provide usage guidance, then suggest help. Every sentence adds value with no wasted words.

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 the tool's complexity (25 params) and the existence of an output schema, the description gives a reasonable overview of purpose and key features. However, it lacks detailed parameter semantics, which could lead to misuse. Adequate but not fully comprehensive.

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% with 25 parameters. Description only broadly mentions 'FieldNames, filters, ordering, etc.' without explaining individual parameter semantics. Refers to tool_help for parameters, but does not compensate within the description itself. For a high-parameter tool, this is insufficient.

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?

Description clearly states 'Build an arbitrary Yandex.Direct statistics report' with specific capabilities like FieldNames, filters, and breakdowns. Explicitly distinguishes from sibling tool reports_get: 'use reports_custom for arbitrary fields & breakdowns; use reports_get for a quick recent snapshot.'

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?

Provides explicit when-to-use guidance contrasting with reports_get and suggests tool_help for parameters. Does not mention when not to use or alternative siblings besides reports_get, but the context is clear.

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