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

Annotations already declare the safety profile (readOnly, idempotent, non-destructive, openWorld), and the description goes well beyond them by disclosing explicit nulls when data is unavailable, source/freshness metadata, and the current-sign and unit conventions. These are the details an agent needs to interpret and trust the returned series.

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?

Purpose is front-loaded and the unit/convention notes are useful. Slightly dense and mildly redundant ('source status' vs 'source/freshness metadata'), but every sentence carries information.

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 supplies the return shape (data plus source/freshness metadata, timestamp, source status, explicit nulls), which is good. The gap is the undocumented 'hours' input for a nested-parameter tool, leaving forecast-window behavior unclear.

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 0%, so the description carries the burden: it clarifies that 'spot' must be a verified spot, adding meaning beyond the regex/maxLength constraints, but it never explains the 'hours' parameter (default 24, range 1-168) that defines the forecast window. Partial compensation only.

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 (predicted inlet currents) for a scoped subject (a verified spot over the next hours). No sibling tool covers inlet currents, so an agent can distinguish it from get_tides, get_gulf_stream or get_waves without opening a 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?

The phrase 'for a verified spot' implies a prerequisite (the spot must already be verified), but there is no explicit when-to-use, when-not-to-use, or routing to alternatives such as get_tides for tidal height. Usage is only implied by the scope.

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