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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine value by disclosing the cost ('10 credits, Tier 1') and the fact that five results are bundled, but it says nothing about response shape beyond the component list and contains the four-vs-five component inconsistency.

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 payload description, followed by short bracket-tagged group and cost metadata. Compact and mostly waste-free, though the bracketed metadata lines are not part of the functional description.

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 an output schema present, the description need not explain return values, and annotations cover the safety profile. It adequately conveys what the tool produces and its cost; the only gap is routing guidance against the seven sibling Mayan tools.

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 67%: `fields` and `precision` carry detailed descriptions while `date` relies only on its YYYY-MM-DD regex pattern. The description adds no parameter guidance at all, so it does not compensate for the undocumented `date` parameter, though the schema largely self-documents the compact-mode options.

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 states a specific verb+resource: it returns the bundled Mayan date components, enumerating Long Count, Tzolkin, Haab, Calendar Round and Lord of the Night. This clearly distinguishes it from the single-component siblings (astroway_mayan_long_count, astroway_mayan_tzolkin, etc.), though it never names those siblings explicitly. Minor flaw: it says 'four classical components' while listing five items.

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 'in one call' implies this is the aggregate alternative to invoking the individual Mayan component tools, but there is no explicit when-to-use/when-not guidance and no named alternatives. Usage is inferable rather than stated.

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