blockrun_defi

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

Beyond the readOnly/openWorld annotations, the description adds meaningful behavioral detail: GET-only requests, per-path pricing in USDC, no API key required, and the caveat that the yields response is large and should be filtered client-side. It also discloses the external data source (DefiLlama). These details materially change how an agent budgets and handles responses.

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?

The description is front-loaded with purpose and cost, then uses a scannable bullet list for the endpoints, followed by concrete examples and sibling routing. Every section contributes either to choosing the tool or calling it correctly; there is no filler.

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 multi-endpoint read tool with no output schema, the description is unusually complete: it lists all endpoints, their costs, example paths, response characteristics ('TVL history + chain breakdown', 'yields with APY + TVL'), and call-size caveats. It also names alternatives so the agent can decide when not to use it. Nothing essential for selection or invocation is missing.

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?

The input schema already documents path and agent_id with examples, so coverage is 100%. The description goes further by explaining endpoint syntax variants like protocol/{slug} and prices/{coins}, giving the coin identifier format ('base:0x833589...,coingecko:ethereum'), and noting per-path costs. This gives the agent enough context to construct valid path values beyond what the schema lists.

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 opens by specifying exactly what the tool does: 'DeFi fundamentals via DefiLlama — protocol TVL, chain TVL, yield pools (APY), token prices.' It then enumerates the five concrete GET paths and gives representative examples. It also names the sibling tools it is not, making distinction immediate.

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 description explicitly routes usage: 'Use blockrun_price (free) for plain spot quotes, blockrun_dex (free) for DEX pairs, blockrun_surf for labeled on-chain data — this tool is for protocol/TVL/yield fundamentals.' This is a clear when-to-use vs when-not-to-use instruction, reinforced by exact path examples for each call shape.

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