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

With no annotations, the description carries the full burden, but it does disclose two genuine behavioral traits beyond the schema: the data is delayed (latency) and cohorts smaller than 2 fills are suppressed (a privacy/threshold rule that explains missing data). It does not state read-only semantics, aggregation window, or what 'delayed' means in practice.

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?

A single compact sentence with the most important qualifier (delayed) first and the suppression rule parenthesized. Nothing is wasted, but the extreme brevity leaves the tool under-described rather than efficiently described.

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?

With no parameters, no annotations, and no output schema, the description is the only source of information about what comes back, and it says almost nothing — no metric definitions, no time window, no dimensions, no granularity. The suppression rule is the one genuinely informative element, which is not enough for a zero-schema aggregate endpoint.

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?

The tool takes zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. The qualifier about >=2-fill cohorts is arguably closer to output semantics than parameter semantics, but no deduction is warranted here.

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 identifies the resource ('post-trade aggregates') and a key qualifier (delayed, cohort of >=2 fills), which hints at the contrast with the sibling 'fills'. However, there is no verb or statement of what the tool actually returns (counts? VWAP? volume?) and no explicit differentiation from siblings like book_view or own_orders.

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?

There is no guidance on when to call this versus fills or book_view; the word 'delayed' implies it is not the live view but the agent must infer that. No prerequisites, no exclusions, no stated alternative.

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