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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world scope, so safety is covered. The description adds value by disclosing the shape of the returned record (sourced facts, notes, vendor description and link), which the annotations cannot convey. It is silent on behavior for an invalid id, but the enum makes that largely moot.

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?

Two tight sentences, front-loaded with the verb and resource, followed by the sequencing hint. The parenthetical enumeration of ids duplicates the enum in the schema, but it costs little and is read at a glance.

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 single-parameter, read-only lookup with no output schema, the description covers purpose, return contents, and the calling sequence with its sibling. Only the absence of any note on failure behavior for an unmatched id keeps it short of full completeness.

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 100% and the id parameter carries an enum of cointracking, divly, koinly, so semantics are fully documented structurally. The description merely restates the same three values, adding no meaning beyond the schema. Baseline 3 applies.

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 and resource ('Get the full sourced record for one crypto tax tool by id') and enumerates the concrete payload (facts, notes, tool's own description and link). This clearly separates it from the sibling search_crypto_tax_tools, which returns matches rather than a full record.

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?

Explicitly routes the agent with 'Use after search_crypto_tax_tools', establishing the lookup sequence and the question it answers ('what does X do for K4?'). It does not state a when-not-to-use condition, but the prerequisite makes the usage context unambiguous.

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