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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing that the calls do not charge the wallet and do not generate, and by documenting concrete failure modes (HTTP 403 without subscription, HTTP 404 when the version is missing). These are exactly the operational traits an agent needs before invoking.

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 core description, then walks each view in sequence with no filler sentences. The prose is telegraphic and occasionally dense, but every clause carries an actionable constraint, so little is wasted.

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?

For a 7-parameter, no-output-schema tool with only safety annotations, this covers view-dependent behavior, auth requirements, and error semantics thoroughly. The only untouched parameter is maxAgeDays, a minor cache-tuning knob already described in the schema.

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 conditional relationships the schema alone does not express: lang is required for the three subscription views, topic pairs with cadence for view=topic, and sources is opt-in. It adds real routing meaning beyond the enum descriptions.

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 resource and retrieval intent ('Market briefing from the shared cache') and enumerates the view modes it serves, so the agent knows exactly what data domain this covers. It does not explicitly differentiate itself from sibling tools like macro or news, but the internal view taxonomy makes the scope unambiguous.

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 clear per-view usage conditions: weekly is always available, daily/cio_view require trader or investor subscriptions, and 403/404 outcomes are spelled out. It stops short of explicitly steering the agent away from siblings or naming when-not-to-use cases, so it is strong context without full alternative routing.

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