fetch_equity_history

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

With no annotations present, the description carries the full burden and does it well: it discloses the ~1h window bound, the 5s sampling cadence, ordering, the credential requirement, and the exact pagination termination condition. These are non-obvious behavioral traits an agent could not infer from the name or schema.

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-loads the most decision-relevant fact (the narrow ~1h window) and the alternative before the pagination detail. Every sentence carries information, though the pagination explanation runs slightly long relative to what the schema cursor description already states.

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?

No output schema exists, yet the description fully documents the return shape (`{ items, next_cursor }`) and the meaning of each field, plus the loop needed to consume it. For a two-parameter read tool, nothing an agent needs to call it correctly is missing.

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%, so the baseline is 3, but the description adds real meaning: it clarifies that `limit` sizes ONE page rather than a total, and frames `cursor` as the value passed back from the previous response. The mechanics of the pagination loop are the notable addition beyond the schema text.

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?

Names a specific resource (the authenticated account's equity time-series) with its defining constraints: 5s cadence, ~1h window, oldest-first ordering. It explicitly distinguishes itself from the sibling `fetch_portfolio_history`, so an agent can disambiguate without opening either schema.

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?

States when to use the alternative ('For a longer window, or for PnL and volume series alongside equity, use fetch_portfolio_history') and gives the operational procedure for exhausting history (call repeatedly with the previous next_cursor until null). Conditions and exclusions are explicit.

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