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

Annotations already cover safety (readOnly, idempotent, closed-world), so the description's value-add is the search methodology and the outcome reporting. It discloses the similarity criteria, the exclusion rules, and the four outcome measures tracked within 12 months, plus interpretive guidance ('history, not a forecast'). It omits edge behavior such as what happens when no close matches exist.

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?

Dense but front-loaded, with the core operation stated first and the constraint clauses and outcome list following. Every clause carries information, though the single run-on sentence requires close reading.

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 usefully enumerates the metrics returned (crisis meter peak, NBER recession, S&P 500 bear market, dollar index) and the qualifications on matches. It is close to complete for this search tool, though it does not specify the response shape or behavior on zero matches.

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 both parameters (date, count) are already documented with formats and defaults. The description implies a date comparison and a default of today but adds no syntax or semantics beyond the schema; 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?

The description names a specific operation: finding historical days since 1990 whose 14 crisis-meter sensors, market-top risk, and recession risk most closely match a given day, and reporting what followed. This is clearly distinguishable from siblings like get_current_readings or get_readings_on_date, which retrieve readings rather than analogs.

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?

It states the default (today) and the qualifying constraints on matches (at least half a year apart, at least a year prior), which implicitly tells the agent when this tool applies. It does not explicitly name alternative siblings or when not to use it, leaving that to inference.

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