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

Annotations already declare readOnlyHint=true and idempotentHint=false, so the safety profile is covered. The description adds one piece of behavioral context — that it returns both 'observed' and 'signed' heights, two distinct values — which is meaningful beyond the annotations, but it says nothing about freshness, caching, or what happens for an unknown chain.

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 sentences, no filler, and the core behavior is front-loaded before the usage hint. Every sentence earns its place.

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 one-parameter read-only lookup with no output schema, the description plus annotations plus full schema coverage give an agent enough to call it correctly. The only real gap is the missing contrast with the sibling get_lastblock.

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 single chain parameter is fully documented in the schema with examples (BTC, ETH, THOR). The description adds no syntax, format, or cardinality detail beyond that, so 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 with scope: 'Returns the last observed and signed block heights for a specific chain.' An agent can tell what it does. It does not, however, explicitly differentiate itself from the sibling get_lastblock, which likely returns the same data without per-chain scoping.

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?

'Useful for monitoring a particular chain's sync status' implies a usage context but gives no explicit when-to-use vs. alternatives (e.g. get_lastblock for all chains) and no exclusions or prerequisites.

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