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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioral context beyond that: gated watchlist sections are stripped from the returned content, and no brief is ever synthesised. What it omits is the failure mode when a date has no brief.

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 short sentences, front-loaded with the core action, then the filtering behavior, then the no-synthesis guarantee. No filler and nothing to trim.

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 output schema, the description correctly carries the return-format burden by stating the payload is markdown and that gated sections are removed. The remaining gap is what happens on a date with no brief, which matters for a tool that explicitly refuses to synthesise.

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 coverage is 100% with a single optional parameter that already documents the YYYY-MM-DD format and the omit-for-latest behavior. The description reinforces 'for a date' but adds no format or edge-case detail beyond the schema, so the baseline 3 applies.

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?

Specific verb and resource: 'Return the public Frontier Signal brief markdown for a date.' This clearly distinguishes it from data-oriented siblings like deltas or demand_mix, though it does not reference list_observed_dates, which is the natural companion for finding valid dates.

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?

'Omit for the latest public brief' gives one selection rule, and 'A brief is never synthesised' implicitly tells the agent not to expect generated content for dates without one. However, it never names list_observed_dates as the way to discover valid dates, so the when-to-use-versus-sibling guidance is only implied.

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