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

Annotations already establish readOnly/idempotent/openWorld=false, so the bar is lower; the description adds meaningful provenance context beyond them — point-in-time replay, only data published by each day, and look-ahead verification. It does not describe return shape or pagination, but the methodological disclosure is real added value.

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?

Front-loaded with the scope and the call-before-claiming directive, then the selectors. The long event list is bulky but each token is a usable enum value rather than filler, so it largely earns its space.

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 does well to explain defaults, section taxonomy, and event addressing, and it hints that summary is short. It never states what the record actually returns or how from_year/to_year constrain the replay, which is the remaining gap for a 4-param tool.

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 50%. The description compensates heavily for the two weak spots: it enumerates every valid section value and, more importantly, lists the full set of event ids/aliases (gulf, ltcm, lehman, covid, tariffs, or year) that the schema only gestures at. It says nothing about from_year/to_year semantics, leaving the remaining half undocumented.

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?

States a specific verb+resource: it returns how Isoba behaved when replayed point-in-time over every working day since 1990, with look-ahead checks. This is plainly distinct from siblings like get_current_readings or find_similar_days, which cover live or analog data rather than historical self-performance.

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?

Gives a concrete usage directive ('Call it before claiming reliability') and explains the default (summary is short) plus the alternative selectors (section vs single event). It does not name sibling tools or explicit when-not-to-use conditions, so it falls short of a 5.

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